31 
in an onshore direction. This is reflected in rapidly changing water levels (e.g. on 18 January 
between 7 and 8 UTC, the sea level at Kotobrzeg changes at a rate of 25 cm/h). As the gale- 
force winds back slightly offshore to a W-SW direction in the early afternoon of 18 January, 
sea levels fall, with lower levels recorded in Sassnitz and Swinoujscie than in Kotobrzeg. 
The impact of the NW storm progressing south of Bornholm is first felt in Kotobrzeg and 
Sassnitz, where the water level begins to rise at 15 UTC, and then in Swinoujscie, at 16 UTC 
on 18 January. The culmination in this part of the coast is reached on 19 January at 9 UTC at 
Swinoujscie (623 cm) and Sassnitz (624 cm) and only one hour later in Kotobrzeg, where the 
maximum is 640 cm. 
In the western part of the coast, levels remained above the alarm water level (580 cm) for 17 
hours in Wismar, 16 hours in Warnemünde, and 35 hours in Sassnitz. In the central part of 
the coast, they were above the alarm level (580 cm) for as long as 31 hours in Swinoujscie, 
and 24 hours in Kotobrzeg (above 610 cm). 
Relative to the reference level indicator (577 cm on 17 January), this surge lasted from 18 
hours in Warnemünde to 38 hours in Kotobrzeg. 
Fig. 6.4.2. Sea level changes during the storm surge of January 1983